Define direct, inverse and joint variation. Direct Variation: where one variable is a constant multiple of another Inverse Variation: when one of the variables increases, the other one decreases

Joint Variation: where are more than two variables are related directly define direct, inverse and joint variation

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west

i think the answer is a and b

i wish you luck